It is known that rotary driveshafts and propeller shafts are often used in the power train designs of modern automotive vehicles. More specifically, it is known that rotary driveshafts are used to drive the front wheels of front wheel drive vehicles and propeller shafts are utilized in driving the rear drive system in rear wheel driven vehicles. In studying the rotational movement of the rotary driveshaft, it is known that certain unbalanced rotation may occur at certain rotational speeds. Undesirable vibrations may be induced into the rotary driveshaft as a result of an unbalanced rotation. These undesirable vibrations often present themselves as bending or torsional forces within the driveshaft during rotation.
It is obvious that bending or torsional forces due to the unbalanced rotation of the rotary driveshafts are not desirable or suitable in the operation of the drive train of most vehicles. It is known to utilize various dynamic dampers and mass dampers to suppress the undesirable vibrations that are induced in the rotary driveshaft due to the unbalanced rotation.
Dynamic dampers are often installed or inserted directly onto the rotary driveshafts. The dynamic damper is designed to generate a prescribed vibrational frequency adjusted to the dominant frequency of the excited harmful vibrations. The dynamic damper converts or transfers the vibrational energy of the rotary drive shaft to the dynamic damper by resonance, and eventually absorbs the vibrational energy of the rotary driveshaft. In short, the dynamic damper attempts to cancel or negate vibrations that are induced onto or caused by the rotary driveshaft in normal operation of the drive train of the vehicle.
It is understood that the ultimate design of front wheel drive rotary driveshafts often depend upon engine compartment space constraints set by the vehicle manufacturers. The eventual size and design of the dynamic damper must therefore be commensurate with the engine compartment design and other vehicle space constraints. Lastly, the dynamic damper must appropriately generate the specific harmonic frequency range that is required to counteract the undesirable vibrations of the rotary driveshaft.
In most powertrain and engine compartment designs, downsizing or reducing the size of most components, including the dynamic damper while still affording the proper horsepower or torque range is desirable. It is therefore important to have a dynamic damper which is as small in overall size as practical while still affording the correct vibrational counteracting frequency range of operation.
U.S. Pat. No. 5,056,763 to Hamada, et al. discloses a dynamic damper. The dynamic damper of Hamada, et al. comprises a pair of ring shaped fixing members spaced apart at a predetermined interval. The dynamic damper of Hamada is inserted onto and supported by the rotary driveshaft. A mass member is disposed between the pair of ring shaped fixing members. A pair of connecting members are then provided to connect the ends of the fixing members to the ends of the mass member. It is noted that the dynamic damper design of Hamada, et al. also requires individual metal clamps to be added on either side and over the ring shaped fixing members to operationally affix the dynamic damper to the rotary shaft. Further, it should be noted that the ring shaped fixing members are spaced apart from the mass member not only in a vertical but also in horizontal direction thereby increasing the overall size of the dynamic damper.
The present invention solves the above noted problems and others in a manner not disclosed in the prior art.